Low-friction bending system in a rolling stand comprising several rolls

ABSTRACT

A device for bending the rolls in a rolling stand having several rolls with the use of bending blocks, which are mounted at the run-in end and the run-out end between the roll chocks and the housing windows and can be acted upon by control elements. A piston-cylinder is assigned to the bending blocks of one of the mill housings, and a vertical positioning mechanism is assigned to the bending blocks of the opposite mill housing.

The present application is a continuation of Ser. No. 10/528,324, filedMar. 18, 2005, which is a National Phase application of PCT/EP03/08223filed Jul. 25, 2003, which in turn claims priority of German application102 43 677.0 filed Sep. 20, 2002, the contents of all of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

The invention concerns a device for bending the rolls in a rolling standcomprising several rolls with the use of bending blocks, which aremounted at the run-in end and the runout end between the roll chocks andthe housing windows and can be acted upon by control elements.

Devices of this general type are used for flatness control of a rolledproduct as control elements for bending the work rolls. The controlelement has a direct effect on the roll gap geometry in the strip edgeregion, such that the work rolls are bent positively around the edge ofthe rolls lying above them and negatively around the edges of therolling stock.

German Patent 22 50 953 describes a rolling stand with work rolls andbackup rolls and a roll bending device, in which the chocks of the workrolls are supported between blocks anchored in the housing windows andare connected by piston-cylinder units, which are assigned to the blocksand can be acted upon on both sides to effect the work roll cambercorrection, such that on each block a lower and an upper guide memberare supported in such a way that they can be moved vertically, whereasone of the guide members holds the cylinder, and the other guide memberis connected with the piston, and the guide members are connected withthe chocks in a positive-locking way in the vertical direction byhorizontal guides, which are continued between the housings parallel tothe rolls for the roll change. In this way, it is intended that twopiston-cylinder units are necessary on each side for roll bending.

This device has proven effective in practice. However, it has thedisadvantage that the cylinders must be arranged on the drive end andthe tending end and on the run-in end and the runout end. This movablesupport of each end necessarily results in high frictional forces,which, in addition, have negative effects on the flatness control.

SUMMARY OF THE INVENTION

The goal of the invention is to reduce frictional forces in a system ofthis general type.

To achieve this goal, it is proposed that a single piston-cylinder beassigned to the bending blocks of one of the mill housings, and that avertical positioning mechanism be assigned to the bending blocks of theopposite mill housing. In this way, the bending blocks of the millhousing on one side of the roll chuck are positioned and locked by thevertical positioning mechanism, and the bending blocks of the millhousing on the other side of the roll chuck introduce the bending forcesfrom the piston-cylinder to the roll. Due to this construction, thebending force is controlled during rolling from only one side of theroll chocks via the single piston-cylinder assigned to the bendingblocks of the mill housing on one side of the roll chock.

The positioning and locking of the bending blocks by means of thevertical positioning mechanism, preferably a spindle-type lifting gearunit, make it possible to produce a center of rotation about which thechock can be rotated. Thus, only one cylinder each is necessary tointroduce the bending force into the bending blocks at the drive end andthe tending end.

By virtue of the fact that there are now only two cylinders being usedin the rolling stand to introduce the bending force into the bendingblocks, the frictional force can be significantly reduced.

The worn zone of the rolls can also be compensated by the spindle-typelifting gear unit.

The device of the invention can also be used for intermediate rollbending in a six-high mill. Use in reversing mills is also conceivable.

The drawings illustrate an embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a side view section of a four-high mill from the drive end.

FIG. 2 shows a top view of the work roll plane of the rolling stand inFIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In a rolling stand 1, the work rolls 3, 3 a are supported by the backuprolls 2, 2 a. The chocks 4, 4 a of the work rolls are connected by thebending blocks 5, 5 a, 5′, 5 a′ with the mill housings 6, 6′. Aspindle-type lifting gear unit 10 is installed between the bendingblocks 5′ and 5 a′ and can be positioned and locked by a drive 12.

The bending blocks 5 and 5 a are connected by a single piston-cylinder7, whose piston 9 is supported in bending block 5 a, while itsconnecting rod 8 is mounted in bending block 5. The bending blocks 5, 5a, 5′ and 5 a′ can be connected by well-known means with the chocks 4, 4a of the work rolls 3, 3 a, on the one hand, and the mill housings 6,6′, on the other hand.

The rolling direction of the rolling stock passing through the mill isindicated by the double arrow 11. Flatness control is accomplished bypositioning and locking the bending blocks 5′, 5 a′ with thespindle-type lifting gear unit, while the piston-cylinder 7, whichconnects the bending blocks 5 and 5 a with each other, introduces thenecessary bending force.

The invention is not limited to the use of spindle-type lifting gearunits, but rather any vertical positioning mechanism can be used, forexample, wedges with restricted guidance, a cylinder with clamping headand position sensor, or an eccentric shaft.

1. Device for bending the rolls in a rolling stand comprising several rolls with the use of bending blocks, which are mounted at the run-in end and the runout end between the roll chocks and the housing windows and can be acted upon by control elements, wherein a single piston-cylinder (7) is assigned to the bending blocks (5, 5 a) of a first one of the mill housings (6) for introducing bending force to the roll, and a vertical positioning mechanism (10) is assigned to the bending blocks (5′, 5 a′) of a second mill housing (6′) opposite the first mill housing (6) so as to position and lock the bending blocks of the second mill housing during rolling for flatness control, the vertical positioning mechanism (10) being configured as a spindle-type lifting gear unit.
 2. Device in accordance with claim 1, wherein a roll change position can be vertically adjusted by the vertical positioning mechanism (10).
 3. Device in accordance with claim 1, wherein the piston-cylinder (7) comprises a piston (8) mounted in one of the bending blocks (5) and a connecting rod (9) to the other bending block (5 a).
 4. Device for bending the rolls in a rolling stand comprising several rolls with the use of bending blocks, which are mounted at the run-in end and the runout end between the roll chocks and the housing windows and can be acted upon by control elements, wherein a single piston-cylinder (7) is assigned to the bending blocks (5, 5 a) of a first one of the mill housings (6) for introducing bending force to the roll, and a vertical positioning mechanism (10) is assigned to the bending blocks (5′, 5 a′) of a second mill housing (6′) opposite the first mill housing (6) so as to position and lock the bending blocks of the second mill housing during rolling for flatness control.
 5. Device in accordance with claim 4, wherein the vertical positioning mechanism (10) is designed as wedges with restricted guidance or as a cylinder with clamping head and position sensor. 